Among experiments concentrating on the visual motor system of monkeys and humans, the first set involved analysis of the mechanisms controlling the generation of rapid or saccadic eye movements in the superior colliculus of awake-behaving monkeys. Previous experiments had demonstrated that a subset of cells within the superior colliculus discharges with a burst of activity before the onset of saccadic eye movements. Cells just deeper to these burst cells also discharge in relationship to saccadic eye movements but without the crisply delineated high-frequency bursts. These cells, characterized by anticipatory discharges in addition to saccade-related bursts, have been called preparatory cells. In the preparatory cell layer, and once the saccade began, there was a continuous change in the spatial distribution of activity. Preparatory cells located progressively more rostral to the initially active zone were progressively activated until the activity reached the rostral pole of the superior colliculus. This moving edge of activity represents a potentially new mechanism for controlling the amplitude of the generated saccadic eye movement. The second set of experiments concerned the use of optic flow stimuli, those stimuli that are generated as we move through the visual environment. We made several psychophysical observations on the human response to the simulated optic flow pattern that we had previously used to test the visual response of neurons in the monkey brain. We observed a striking illusion in the optic flow pattern. When we superimposed a field of moving dots on the pattern of radially moving dots, we found that human subjects mislocated the center of this radial pattern; they consistently indicated that the center was shifted in position. We think this illusion reveals a strategy used in separating the location of the center of the optic flow pattern from the confounding movement of other objects in the visual field as one moves through the visual environment.